1. Field of the Invention
In the paper pulp recovery industry, de-inking of the pulp of recycled used paper is known to be performed by blowing air into said pulp.
2. Description of the Prior Art
European patent EP 0,305,251 granted to the applicant hereof discloses an air injector of a particular shape enabling a large quantity of air to be blown into a mass of paper pulp to be de-inked and shaped, as well as a large number of air bubbles (operation known as foaming), the ink contained in the pulp thus foamed then attaches itself to the walls of the air bubbles. All that remains to be done is to separate the ink-laden foam from the semi-liquid mass comprised by water and paper pulp.
The injector described in European patent EP 0,305,251 comes in three parts: a set of tubes for injecting the ink-laden pulp; a cylindrical chamber into which air is blown tangentially; a mixing duct comprising a convergent portion and a divergent portion connected together by a cylindrical duct.